Antenna device

Abstract

An antenna device includes a first antenna and a second antenna provided in a case. The first antenna includes a first capacitance loading element and is configured to at least one of receive and transmit a signal in a first frequency band. The second antenna includes a second capacitance loading element and is configured to at least one of receive and transmit a signal in a second frequency band. The second frequency band is higher than the first frequency band. The second capacitance loading element is disposed at a front side of the first capacitance loading element.

What is claimed: 
     
       1. An antenna device, comprising:
 a first antenna and a second antenna provided in a case, wherein 
 the first antenna includes a first capacitance loading element and is configured to at least one of receive and transmit a signal in a first frequency band, 
 the second antenna includes a second capacitance loading element and is configured to at least one of receive and transmit a signal in a second frequency band, 
 the second frequency band is higher than the first frequency band, and 
 the second capacitance loading element is disposed at a front side of the first capacitance loading element in a front direction, wherein a front-rear direction is a longitudinal direction of the antenna device and the front direction corresponds to an advancement direction of a vehicle when the antenna device is attached to the vehicle and wherein a left-right direction is perpendicular to the front-rear direction and is a width direction of the antenna device, 
 wherein the second antenna comprises a first portion and a second portion, and 
 wherein the second portion is a portion that is bent from the first portion in the left-right direction. 
 
     
     
       2. The antenna device according to  claim 1 , wherein
 the first capacitance loading element and the second capacitance loading element are configured not to overlap to each other in a front-rear direction. 
 
     
     
       3. The antenna device according to  claim 1 , further comprising:
 a third antenna provided in the case, wherein 
 the third antenna is configured to at least one of receive and transmit a signal in a third frequency band, 
 the third frequency band is higher than the second frequency band, and 
 the third antenna is disposed at a front side of the second capacitance loading element. 
 
     
     
       4. The antenna device according to  claim 3 , wherein
 the first capacitance loading element, the second capacitance loading element and the third antenna are configured not to overlap to each other in the front-rear direction. 
 
     
     
       5. The antenna device according to  claim 1 , wherein
 the first antenna includes a first helical element between the first capacitance loading element and a first feeding point, and 
 the second antenna includes a second helical element between the second capacitance loading element and a second feeding point. 
 
     
     
       6. The antenna device according to  claim 5 , wherein
 an axial direction of the first helical element and an axial direction of the second helical element are substantially parallel to each other. 
 
     
     
       7. The antenna device according to  claim 6 , further comprising:
 a base, wherein 
 the axial direction of the first helical element and the axial direction of the second helical element are substantially perpendicular to the base. 
 
     
     
       8. The antenna device according to  claim 5 , wherein
 a distance between an axis of the first helical element and an axis of the second helical element in a front-rear direction is larger than a distance between the first capacitance loading element and the second capacitance loading element in the front-rear direction. 
 
     
     
       9. The antenna device according to  claim 5 , wherein
 a diameter of the first helical element is different from a diameter of the second helical element. 
 
     
     
       10. The antenna device according to  claim 1 , wherein
 a feeding point is disposed at a front side of the first capacitance loading element, and a second feeding point is disposed at a front side of the second capacitance loading element. 
 
     
     
       11. The antenna device according to  claim 1 , further comprising:
 a first board; and 
 a second board which is a separated member from the first board, wherein 
 the first board includes a first feeding point, and 
 the second board includes a second feeding point. 
 
     
     
       12. The antenna device according to  claim 11 , wherein
 the first board is opposed to the second capacitance loading element. 
 
     
     
       13. The antenna device according to  claim 1 , wherein
 each of the first capacitance loading element and the second capacitance loading element is a metal sheet component. 
 
     
     
       14. An antenna device, comprising:
 a first antenna and a second antenna provided in a case, wherein 
 the first antenna includes a first capacitance loading element and is configured to at least one of receive and transmit a signal in a first frequency band, 
 the second antenna includes a second capacitance loading element and is configured to at east one of receive and transmit a signal in a second frequency band, 
 the second frequency band is higher than the first frequency band, and 
 the second capacitance loading element is disposed at a front side of the first capacitance loading element, 
 the first antenna includes a first helical element between the first capacitance loading element and a first feeding point, 
 the second antenna includes a second helical element between the second capacitance loading element and a second feeding point, and 
 an axial direction of the first helical element and an axial direction of the second helical element are substantially parallel to each other. 
 
     
     
       15. The antenna device according to  claim 14 , wherein
 the first capacitance loading element and the second capacitance loading element are configured not to overlap to each other in a front-rear direction. 
 
     
     
       16. The antenna device according to  claim 14 , wherein
 a distance between an axis of the first helical element and an axis of the second helical element in a front-rear direction is larger than a distance between the first capacitance loading element and the second capacitance loading element in the front-rear direction. 
 
     
     
       17. The antenna device according to  claim 14 , wherein
 a diameter of the first helical element is different from a diameter of the second helical element. 
 
     
     
       18. The antenna device according to  claim 14 , wherein
 a feeding point is disposed at a front side of the first capacitance loading element, and a second feeding point is disposed at a front side of the second capacitance loading element. 
 
     
     
       19. The antenna device according to  claim 14 , further comprising:
 a first board: and 
 a second board which is a separated member from the first board, wherein 
 the first board includes a first feeding point, d 
 the second board includes a second feeding point. 
 
     
     
       20. The antenna device according to  claim 1 , wherein the first portion has a triangular shape and the second portion has a rectangular shape, and the second portion is bent downwards with respect to a side of the first portion such that it extends in the left-right direction.